1. Field of the Invention
The present invention relates to a process for producing a peroxidase using a microorganism. More particularly, the invention relates to a process for producing a peroxidase that is produced by a fungi of the genus Coprinus of the basidiomycetes and which develops color with the aid of a hydrogen donor such as a 4-amino-antipyrine (hereunder abbreviated as 4-AA)-phenol system, a 3-methyl-2-benzothiazolinone hydrazone (hereunder MBTH)-diethylaniline (hereunder DEA) system, and a 2,2'-azino-di(3-ethylbenzothiazoline)-6-sulfonic acid (hereunder ABTS).
2. Prior Art
Peroxidase is an enzyme that oxidizes a variety of compounds in the presence of hydrogen peroxide. Currently, peroxidase is used as a clinical or diagnostic reagent in combination with a variety of oxidases for the assay of glucose, cholesterol, phospholipids and uric acid. Another current use of peroxidase is as a marker enzyme in enzyme immunoassay. The only commercially available sources of peroxidase are plants such as horseradish and Japanese radish. Since the peroxidase originating from such plants contains isozymes of slightly different properties, they must be separated laboriously in order to obtain a pure form of peroxidase suitable for use as a diagnostic reagent.
Peroxidases originating from microorganisms are also known and they include Cytochrome C peroxidase and NADH peroxidase produced from bacteria and fungi. However, these peroxidases are not non-specific as are the ordinary peroxidases derived from horseradish and Japanese radish, and such peroxidases specific to a particular system are not suitable for use as clinical and diagnostic reagents. It has recently been reported that peroxidase using o-dianisidine as a hydrogen donor can be produced from E. coli or microorganisms of the genus Myrothecium. However, this peroxidase is also unsuitable as a diagnostic reagent since the use of o-dianisidine in clinical and diagnostic agents is increasingly discouraged because of its potential carcinogenic effects.